In modern society, mobile terminals have been rapidly distributed due to the mobile terminal's convenience and necessity, and now, the mobile terminal has become a necessity of a modern people. Therefore, service providers and terminal manufacturers provide numerous additional functions in order to increase utility of the mobile terminal. For example, the mobile terminal includes functions such as a phone book, games, a scheduler, Short Message Service (SMS), multimedia message service, cell broadcasting service, an Internet service, an electronic (E)-mail, a morning call, Motion Picture Expert Group Audio Layer-3 (MP3), a digital camera, and so forth.
Of the above-listed various functions provided through the mobile terminal, SMS is one of most frequently used functions in the mobile terminal. Messages received and transmitted through the SMS are stored in a memory inside the mobile terminal. Therefore, a user can perform management functions such as search, check, delete, return, and the like with respect to messages transmitted and received in the past. For example, when a user intends to check contents of a stored message, a mobile terminal aligns and displays the stored messages in an order of a transmission time or a reception time. Additionally, when the user selects one of the aligned messages, the mobile terminal displays contents of the selected message.
Recently, studies of propensity to use of SMS by users show that two users engage in a conversation by giving and taking messages between them. In this case, the messages exchanged between the two users have a relation in their contents. Therefore, in the case where a user checks contents of a stored message, the user desires to check contents of related messages together. However, a message display function of a current mobile terminal cannot meet the above-described demand of users, and moreover, does not have even a capability of identifying related messages.